|- (A->B) -> (B->C) -> A -> C




                           [A]       [B -> C]
                           __________________
     		                   B               [B -> C]
                                   ___________________________
                                               C
                                         ______________
                                             A -> C
                                     ______________________
                                        (B->C) -> A -> C
                        _______________________________________________
                                   (A->B) -> (B->C) -> A -> C